This invention pertains to the preparation of alkoxylated alcohols. More specifically, this invention relates to an improvement in the reaction of an alkylene oxide and a long chain alcohol in the presence of a calcined hydrotalcite catalyst wherein insoluble by-products formed in the reaction are readily removed.
Alkoxylated alcohols, especially ethoxylated long chain alcohols, have long been known to be useful as surfactants. It has been found that some ethoxylated long chain alcohols are also useful as mosquito control agents. These ethoxylated alcohols are applied as an approximately monomolecular film to a body of water containing immature forms of mosquitos. The presence of the monomolecular film prevents the emergence of the adult from its aquatic breeding site. Ethoxylated isostearyl alcohol has been found to be especially useful as a mosquito control agent. However, attempts to synthesize ethoxylated isostearyl alcohol which is acceptable for spraying onto a body of water have resulted in failure because the ethoxylated isostearyl alcohol was found to be poorly dispersible in water and exhibited an unacceptably high freezing point.
The use of calcined hydrotalcite as an ethoxylation catalyst produced material which is readily dispersed in water and which had an acceptable freezing point. However, the material was found to contain hazy insoluble white matter which clogged spray nozzles when sprayed onto bodies of water for mosquito control. Therefore, a method of eliminating the presence of the nozzle-clogging material was sought. An object of the invention, therefore, is an alkoxylated alcohol made by the alkoxylation of an alcohol in the presence of a calcined hydrotalcite catalyst that does not contain hazy insoluble matter. A further object of the invention is an ethoxylated isostearyl alcohol that contains no hazy insoluble matter which can clog spray nozzles when sprayed onto bodies of water for mosquito control.